Hello Thomas,
Thanks a lot for your feedback.
On 9/30/22 10:26, Thomas Zimmermann wrote:
Hi
Am 30.09.22 um 10:01 schrieb Javier Martinez Canillas:
The drm_atomic_helper_damage_merged() helper merges all the damage clips
into one rectangle. If there are multiple damage clips that aren't close
to each other, the resulting rectangle could be quite big.
Instead of using that function helper, iterate over all the damage clips
and update them one by one.
Suggested-by: Jocelyn Falempe <jfalempe@xxxxxxxxxx>
Signed-off-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
---
drivers/gpu/drm/solomon/ssd130x.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c
index bc41a5ae810a..2428f1813a8d 100644
--- a/drivers/gpu/drm/solomon/ssd130x.c
+++ b/drivers/gpu/drm/solomon/ssd130x.c
@@ -578,21 +578,23 @@ static void ssd130x_primary_plane_helper_atomic_update(struct drm_plane *plane,
struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state, plane);
struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
+ struct drm_atomic_helper_damage_iter iter;
struct drm_device *drm = plane->dev;
- struct drm_rect src_clip, dst_clip;
+ struct drm_rect dst_clip;
+ struct drm_rect damage;
int idx;
- if (!drm_atomic_helper_damage_merged(old_plane_state, plane_state, &src_clip))
- return;
-
dst_clip = plane_state->dst;
- if (!drm_rect_intersect(&dst_clip, &src_clip))
- return;
-
if (!drm_dev_enter(drm, &idx))
return;
- ssd130x_fb_blit_rect(plane_state->fb, &shadow_plane_state->data[0], &dst_clip);
+ drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
+ drm_atomic_for_each_plane_damage(&iter, &damage) {
+ if (!drm_rect_intersect(&dst_clip, &damage))
+ continue;
dst_clip will be overwritten here. So need to init it within the loop first.
Oh, indeed. I'll move it inside the loop. Thanks for catching this.
+
+ ssd130x_fb_blit_rect(plane_state->fb, &shadow_plane_state->data[0], &damage);
In simpledrm, we adjust the destination address with dst_clip like this:
iosys_map_incr(&dst, drm_fb_clip_offset(sdev->pitch, sdev->format,
&dst_clip));
How does this work in ssd130x? You never use dst_clip to adjust to the
changed location. Won't you have out-of-bounds writes on the device?
Right, in ssd130x what I do is:
static int ssd130x_fb_blit_rect(struct drm_framebuffer *fb, const struct iosys_map *vmap,
struct drm_rect *rect)
{
struct iosys_map dst;
...
u8 *buf = NULL;
...
buf = kcalloc(dst_pitch, drm_rect_height(rect), GFP_KERNEL);
...
iosys_map_set_vaddr(&dst, buf);
drm_fb_xrgb8888_to_mono(&dst, &dst_pitch, vmap, fb, rect);
...
ssd130x_update_rect(ssd130x, buf, rect);
}
I understand that's correct too?
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